Automatic doors for a dumbwaiter system



July 12, 1966 c. F. STEWART AUTOMATIC DOORS FOR A DUMBWAITER SYSTEM Filed Feb. 10, 1965 I )11 I I 26 2r I 25/ I r I 15 l I 3d I INLET I F L 1 11:2251 L I V31 I 24 fizz #3, 13 I 25 21/ 23 29 H I l l V I 14' l [/16 CLOSE I HII [EIIREOPEN I 30 f 32 l 26 L l INVENTOR Charles F Ste wart v BY flaw United States Patent 3,260,330 AUTOMATIC DOORS FOR A DUMBWAITER SYSTEM Charles Francis Stewart, Poughkeepsie, N.Y., assignor to Sedgwick Machine Works, Inc., Poughkeepsie, N.Y., a corporation of New York Filed Feb. 10, 1965, Ser. No. 431,547 6 Claims. (Cl. 1873) This invention relates to power operated dumbwaiter systems and, more particularly, to a fluid pressure actuated door for the dumbwaiter enclosure at each of the floors serviced by the dumbwaiter.

It is a feature of the invention that, in addition to being desirable in new installations, the arrangement hereinafter described may be conveniently added to already existing dumbwaiter installations.

It is the main object of the invention to provide in a dumbwaiter installation a fluid pressure actuated enclosure door which opens automatically when the dumbwaiter car has reached and stopped at a specific position at the calling floor.

It is another object of the invention to provide a first automatic detection device operable in conjunction with the usual dumbwaiter car driving means whereby actlvation of the pressure actuated enclosure door operating device to open the door at any floor of the dumbwaiter installation is prevented while the car driving means is energized.

It is a further object to provide at each enclosure doorway a means operable by the car when the same has stopped in a specific position at the calling floor whereby the pressure actuated enclosure door operating device for the door at that floor is automatically activated to open that door.

It is an additional object to provide a manual means at the doorway whereat the car is at rest operable to activate the pressure actuated enclosure door operating device for the door at that floor to close an already opened door at that doorway.

It is a still further object to provide an additional man ual means at the doorway whereat the car is at rest operable in conjunction with a second automatic detection device included in the usual door interlock circuitry of a powered dumbwaiter installation to activate the pressure actuated enclosure door operating device for the door at that floor to reopen that door.

Other objects and features of the invention will be apparent from the hereinafter set forth description taken in conjunction with the accompanying drawing which illustrates schematically a preferred embodiment of the invention comprised of electrical and mechanical components cooperating in accordance with the above objects.

Powered dumbwaiter systems per se comprised of a hoistway structure, an enclosure therefor having doors therein, and a car adapted for travel within the hoistway and enclosure under control of the usual electrical circuitry, including the door interlock or aspect circuitry associated with the enclosure doors, together with the usual mechanical components utilized for moving the car, are well known to those familiar with such systems and, accordingly, are not described and/or illustrated in detail in connection with the present invention. However, certain elements of the present invention are inserted in the previously noted usual electrical circuitry and serve as detection devices as to the condition of that circuitry.

One of these elements, relay SA, is arranged in the usual car driving means power circuit in such a way that it is energized whenever the car is being driven, and another element, relay BL is arranged in the usual door interlock circuit in such a way that it is energized when all of the 3,260,333 Patented July 12, 1966 enclosure doors of the system are closed. A third element of the present invention, relay DC, is included in the circuitry of this invention established by the above noted condition detection device and its operation is controlled by manual means provided at each enclosure doorway. The function and operation of this element will be described in detail hereinafter.

In addition to the above elements of the present inven tion which are preferably arranged at the main control panel for the dumbwaiter installation and which function to control the electrical power distribution to the enclosure door controls according to this invention at each floor serviced by the dumbwaiter, the following devices, individual to each floor serviced by the dumbwaiter, are installed at and secured to the hoistway enclosure H adjacent to the doorway therein at each floor: A switch CS tensioned in one position and movable to another position by a cam CA carried by the car, a cylinder RP having a reciprocally movable piston therein operatively connected to the enclosure door D, a four-way valve V having a plug VP therefor, a solenoid DS tensioned in one position and operatively connected to the plug VP, fluid pressure circuit piping 17 and 18 interconnecting the cylinder RP and the valve V whereby the direction of movement of the piston is controlled by the position of the plug VP of valve V, and two manually operated electrical switches, one of the make type and the other of the break type.

The usual power circuit for the dumbwaiter driving motor M is represented in the drawing by the bracketed lines 10, the usual interlock circuit for the dumbwaiter enclosure doors is represented by the bracketed lines 11, and the power circuit for operating the electrical equipment included in the present invention is indicated by the bracketed lines 12. A main fluid pressure line secured within the hoistway enclosure is indicated at 13 and a pump for maintaining a pressure in that line is indicated at 13a. A branch line, such as that shown at 13b, serves to connect the main pressure line 13 to the mechanical equipment items V and RP of the present invention arranged at each floor serviced by the dumbwaiter system. A multi-wire cable secured within the hoistway enclosure is represented by the bracketed lines 14 and serves to interconnect the electrical equipment items of the present invention arranged at each floor serviced by the dumbwaiter system and the other electrical equipment items of the present invention previously noted as being preferably arranged on or adjacent to the main control panel for the system.

It will be clearly seen by referring to the drawing, wherein the equipment arranged on or adjacent to the main control panel is represented within the dash-line enclosure 15 and the equipment secured to the hoistway enclosure adjacent to each doorway therein is represented within the dashed-line enclosure 16, that no flexible cable and/ or piping extending between the main control panel and the car is required by this invention for either the electrical or fluid pressure circuits incident hereto. Through such an arrangement, the feature of the invention has been achieved. In addition, an inspection of the drawing will disclose that relay SA, previously noted as being energized Whenever the car driving motor M is energized to move the car, serves through its back contacts 1 and 2 as the only means for connecting the power lines 12 to the enclosure door operating means herein disclosed. Accordingly the enclosure door operating means and the controls therefor are rendered non-effective whenever the car is in motion.

When the car, under the control of the usual equipment, arrives at and stops in the specific position opposite the enclosure doorway of the calling floor, the door at that doorway will open automatically under the control of the equipment according to this invention. When the car has come to rest at the specific position \for the calling floor, the relative position of the cam CA carried by the car and the cooperating crank arm CAA pivotally mounted on the hoistway enclosure H adjacent that doorway, is as shown in the drawing, that is, the cam CA has caused crank arm CAA to move to the right against the indicated tension (to the left) thereon thereby closing contacts 1 and 2 of the switch CS operated by the crank arm CAA. With the car driving motor M deenergized, the relay SA deenergizes and power from lines 12 is connected to the enclosure door control circuitry to energize solenoid DS via one side of the power line 12 at contact 1 of relay SA, wire 20 of cable 14, branch wire 21, winding of solenoid DS, wire 22, contact .1 of closed switch CS, branch wire 23, wire 24 of cable 14, back contact 1 of relay DC, branch wire 25, and wire 26 of cable I14 to the other side of the power line 12 at contact 2 of relay. SA. The solenoid DS is operatively connected by the spring loaded crank arm DSA to a shaft VS secured to the plug VP of the four-way valve V. When the solenoid DS is energized per the above circuit, the crank arm DSA connected thereto rotates the shaft VS, and the plug VP carried thereby, 90. With the plug VP in the so-rotated position, the fluid under pressure in the main pressure line 13 and branch line 13b enters one side of valve V via port 1, leaves that side via port 2, passes through pipe .17, and enters the cylinder RP at its right end thereby causing the piston therein to move to the left. The exhaust from cylinder RP leaves from the left end thereof, passes through pipe 18, enters the other side of valve V via port 3 and is exhausted therefrom v-ia port 4. As will be seen from the schematic representation in the drawing, the piston within the cylinder RP at each doorway is operatively connected to the door D for that doorway. Accordingly, the abovedescribed movement of the piston to the left moves the door D operatively connected thereto to its open aspect. With the door open, the usual door interlock circuitry 11, together with relay DL connected therein, deenergizes and, as a consequence thereof, the usual power circuit for the motor M is broken and, accordingly, the car may not be operated so long as the door remains in its open aspect.

When it is desired to close the door D, the CLOSE (make-type) switch at that floor is manually depressed and held depressed until the movement of the door to its closed position is completed. The circuit established by the continued depression of the CLOSE switch energizes relay DC at the main control panel which, in turn, opens back contact 1 of that relay and thereby opens the previously established energizing circuit for solenoid DS. The circuit for energizing relay DC is from one side of the power line 12 at contact 1 of relay SA, wire 27, winding of relay DC, wire 28 of cable 14, branch wire 29, closed contacts of CLOSE switch, wire 30, contact 2 of switch CS, branch wire 26, and wire 26 of cable 14 to the other side of the power line 12 at contact 2 of relay SA. With solenoid DS deenergized, the indicated tension (to the right) on the crank arm DSA drives shaft VS and causes the plug VP of the valve V to rotate 90 back to the position shown in the drawing whereupon fluid under pressure in the main pressure line 13 and the branch line 13b enters one side of the valve V at port 1, leaves that side via port 3, passes through pipe 18 and enters the cylinder RP at the left end thereof and moves the piston therein to the right. The exhaust from the cylinder RP leaves from its right end, passes through 17, enters the other side of valve V via port 2 and is exhausted therefrom via port 4. Such movement of the piston to the right closes the door D operatively connected thereto.

When the closure of the door D has been completed, the usual door interlock circuity 11, together with relay DL connected therein, is re-energized. The re-activation of relay DL when the door D is fully closed establishes a holding circuit for relay DC and a continued manual depression of the CLOSE switch is no longer necessary. The holding circuit for relay DC is from one side of the power line 12 at contact 1 of relay SA, wire 27, winding of relay DC, wire 28 of cable 14, branch Wire 29', front contact 1 of relay DL, wire 30, front contact 2 of relay DC, wire 31 of cable 14, closed contacts of RE- OPEN switch, wire 32, contact 2 of switch CS, branch Wire 26, and wire 26 of cable 14 to the other side of the power line 12 at contact 2 of relay SA. With this circuitry established, the door D at the fioor whereat the car is at rest now will remain closed and the usual power circuit 10 for the motor M may be activated in its usual manner in response to a call for the car from another floor.

It will be noted from the drawing that the abovedescribed holding circuit for relay DC, requires a separate set of contacts 2 at that relay and a separate wire 31 within the cable 14 for each floor serviced by the dumbwaiter car.

Should it be desired to reopen the door D at any floor before the car has moved away from its specific position at that floor, a momentary depression of the REOPEN (break type) switch at that floor will break at that point the previously described holding circuit for relay DC. The deenergization of relay DC remakes back contact 1 of that relay and re-establishes the likewise previously described energizing circuit for solenoid DS which, in turn, brings about a new opening of door D.

In the foregoing description and in the appended claims, it will be understood that the phrase pressure actuated enclosure door operating device refers to the combination of the solenoid DS, the valve V, and the cylinder RP having a reciprocating piston therein operatively connected to the enclosure door D, together with the fluid pressure circuit piping 17 and 18 interconnecting the valve and the cylinder, all of which function together as a unit in the manner described.

It will thus be seen that all of the specific objects set forth above, together with others which may be apparent from the preceding description, are efiiciently attained by the disclosure of the present invention and, since certain changes may be made in the above described constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawing shall be interpreted as being illustrative and not in a limiting sense. It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention which, as a matter of language, might be said to fall therebetween.

I claim:

1. In a dumbwaiter system including a hoistway structure and an enclosure therefor having a plurality of doorways therein,

a normally closed door in each enclosure doorway adapted for movement relative to the enclosure to an open and to a closed aspect,

an electrical door aspect circuit adapted to be completed when all doors in the system are closed,

a car having a cam arranged thereon and adapted to travel along the structure within the enclosure therefor between a position remote from each doorway to a specific position at each doorway, and

means for moving the car, the improvement comprising, in combination,

a fluid pressure system including a pressure operated reciprocating means, and a solenoid operated control valve therefor, arranged within the enclosure ad jacent each doorway therein,

each reciprocating means being operatively connected to the door at that doorway and adapted to move the said door between its open and closed aspect,

means arranged adjacent each enclosure doorway preventing movement of the door thereat to its open aspect except when the car is at rest in the said specific position at that doorway, and

a detection means responsive to the deactivation of the car moving means for activating the solenoid operated control valve to initiate movement of the reciprocating means at that doorway whereat the car is at rest in the specific position to automatically move that door to its open aspect.

2. A dumbwaiter system according to claim 1, in which the means arranged adjacent each enclosure doorway preventing movement of the door thereat to its open aspect except when the car is at rest in the said specific position at each doorway is an electrical switch tensioned in one position and operable to a second position by the said cam afiixed to the said car.

3. A dumbwaiter system according to claim 1, in which the detection means responsive to the deactivation of the car moving means for initiating movement of the reciprocating means is a relay operable only when the car moving means is deactivated.

4. A dumbwaiter system according to claim 1, in which the solenoid operated control valve for each pressure operated reciprocating means is tensioned in one position and operable to a second position in response to the deactivation of the car moving means,

5. In a dumbwaiter system according to claim 1, the combination also including means for reinitiating movement of the said reciprocating means at the said doorway whereat the car is at rest to move that door from its open to its closed aspect, said means comprising an electrical circuit including a relay and a manually operated switch of the make type adapted to complete the circuit, the relay when activated being adapted to bring about movement of the said control valve to its said one position.

6. In a dumbwaiter system according to claim 1, the combination also including means for reinitiating movement of the said reciprocating means at the said doorway whereat the car is at rest to move the door from its closed to its open aspect, said means comprising a completed electrical circuit established by a detection means responsive to the completion of the said door aspect circuit and including a relay and a manually operated switch of the break type adapted to break the said completed circuit and deactivate the said relay, the relay when deactivated being adapted to bring about movement of the said control valve to its said second position.

References Cited by the Examiner UNITED STATES PATENTS 839,314 12/1906 Payne 187-54 1,557,309 10/1925 Norton 187-31 1,698,362 1/1929 Dugan 18754 1,934,590 11/1933 Ellis 187-54 1,949,788 3/1934 Dunn 18735 X SAMUEL F. COLEMAN, Primary Examiner. 

1. IN A DUMBWAITER SYSTEM INCLUDING A HOISTWAY STRUCTURE AND AN ENCLOSURE THEREFOR HAVING A PLURALITY OF DOORWAYS THEREIN, A NORMALLY CLOSED DOOR IN EACH ENCLOSURE DOORWAY ADAPTED FOR MOVEMENT RELATIVE TO THE ENCLOSURE TO AN OPEN AND TO A CLOSED ASPECT, AN ELECTRICAL DOOR ASPECT CIRCUIT ADAPTED TO BE COMPLETED WHEN ALL DOORS IN THE SYSTEM ARE CLOSED, A CAR HAVING A CAM ARRANGED THEREON AND ADAPTED TO TRAVEL ALONG THE STRUCTURE WITHIN THE ENCLOSURE THEREFOR BETWEEN A POSITION REMOTE FROM EACH DOORWAY TO A SPECIFIC POSITION AT EACH DOORWAY, AND MEANS FOR MOVING THE CAR, THE IMPROVEMENT COMPRISING, IN COMBINATION, A FLUID PRESSURE SYSTEM INCLUDING A PRESSURE OPERATED RECIPROCATING MEANS, AND A SOLENOID OPERATED CONTROL VALVE THEREFOR, ARRANGED WITHIN THE ENCLOSURE ADJACENT EACH DOORWAY THEREIN, EACH RECIPROCATING MEANS BEING OPERATIVELY CONNECTED TO THE DOOR AT THAT DOORWAY AND ADAPTED 